1. Technical Field
The present invention relates to an external storage device with a high tamper-proof property and a method of manufacturing an external storage device.
2. Related Art
In the business of making money by selling content, an external storage device in which the content is stored, for example, a memory card may be sold. In such a business model, the content stored in an external storage device is increasingly read by a dedicated device in recent years. When the external storage device is formed by a typical memory card, the information is transmitted to the dedicated device using a contact type external terminal (for example, see Japanese Unexamined patent publication NO. 2009-105126).
In addition, Japanese Unexamined patent publication NO. 2002-083894 discloses performing non-contact type transmission of the information to the outside by providing an antenna coil in a semiconductor chip.
In the business of making money by selling content, it is important to suppress illegal duplication of the content, that is, to improve the tamper-proof property. A general method for improving the tamper-proof property depends on software processing, such as encryption of the content. However, even if the tamper-proof property is ensured by software processing, it becomes possible to read the contents if software which lowers the tamper-proof property, such as decryption software, is created. Thus, it has been difficult to sufficiently ensure the tamper-proof property.